analysis_date = "2025-09-03"
load(paste0("savepoints/savepoint_",analysis_date,"/brs_3.Rdata"))
source("R/setup.R")
knitr::opts_chunk$set(echo = FALSE)
set_gtsummary_theme(list(
  "tbl_summary-fn:percent_fun" = function(x) style_percent(x, digits = 1)
))

1 Sociodemography and exposure

1.1 Sociodemography

Table 1. Socio-demographic characteristics of respondents.
Characteristic N = 9911
What sex were you assigned at birth?
    Female 557 (56.2%)
    Male 434 (43.8%)
    Intersex 0 (0%)
Which of the following labels best describes your social and felt gender?
    Female 550 (56.1%)
    Male 427 (43.5%)
    Other 4 (0.41%)
    (Missing) 10
What is your highest completed education?
    None 1 (0.11%)
    Incomplete compulsory schooling 1 (0.11%)
    Compulsory schooling 22 (2.32%)
    One-year transitional program 4 (0.42%)
    General education school 16 (1.69%)
    Apprenticeship/vocational school 182 (19.2%)
    Gymnasial maturity 52 (5.49%)
    Professional maturity 18 (1.90%)
    Federal diploma exam 101 (10.7%)
    Higher vocational school 114 (12.0%)
    Bachelor degree 138 (14.6%)
    Master degree 215 (22.7%)
    Doctorate/habilitation 84 (8.86%)
    (Missing) 43
Since when have you been living in Switzerland?
    Since birth 740 (74.9%)
    Born in Switzerland but also lived abroad 60 (6.07%)
    Born abroad 188 (19.0%)
    (Missing) 3
What is your marital status?
    Married, living with spouse 529 (55.5%)
    Married, permanently separated 10 (1.05%)
    Registered partnership, living together 3 (0.31%)
    Registered partnership, separated 1 (0.10%)
    Single, stable partnership 150 (15.7%)
    Single, living alone 126 (13.2%)
    Divorced 96 (10.1%)
    Widowed 38 (3.99%)
    (Missing) 38
Occupation according to CH-ISCO 2019
    Administrative support staff 186 (31.7%)
    Directors, senior executives and managers 3 (0.51%)
    Intellectual and scientific professions 59 (10.1%)
    Intermediate occupations 230 (39.2%)
    Personal services staff, shopkeepers and sales assistants 108 (18.4%)
    (Missing) 405
1 n (%)

1.2 Exposures from inclusion questionnaire

Almost all participants (98.2%) reported having received vaccines at some point, and most indicated full mobility, with 87.1% having no problems walking and fewer than 4% reporting moderate to severe difficulties. A large majority (99.8%) had traveled abroad for more than two days, with Europe being the most frequently visited continent (94%), followed by North America (60.4%), Asia (54.1%), and Africa (46.5%). When asked about future pandemic preparedness, respondents highlighted the importance of combating misinformation (69.7%) and maintaining public awareness (68.2%) and government commitment (55.8%). Other challenges mentioned included strengthening pathogen surveillance (35.4%) and addressing regulatory barriers in vaccine production (28.6%), while climate change mitigation (18.2%) and ventilation improvements (12.8%) were less commonly emphasized.

Table 2. Exposures from inclusion questionnaire.
Characteristic N = 9911
Have you ever received any vaccines?
    Yes 960 (98.2%)
    No 18 (1.84%)
    (Missing) 13
Please select what best describes your mobility today
    I have no problems walking around 844 (87.1%)
    I have slight problems walking around 89 (9.18%)
    I have moderate problems walking around 28 (2.89%)
    I have severe problems walking around 8 (0.83%)
    I am unable to walk around 0 (0%)
    (Missing) 22
Have you ever stayed abroad for more than two days?
    Yes 955 (99.8%)
    No 2 (0.21%)
    (Missing) 34
On which continent?
Europe 932 (94.0%)
North America 599 (60.4%)
Central America 184 (18.6%)
South America 243 (24.5%)
Africa 461 (46.5%)
Asia 536 (54.1%)
Oceania 215 (21.7%)
    (Missing) 0
Thinking about the next pandemic, what do you see as the main challenges for preparedness?
Maintaining public awareness of a possible pandemic 676 (68.2%)
Maintaining government commitment to pandemic preparedness 553 (55.8%)
Mitigating the effects of climate change 180 (18.2%)
Regulatory barriers to scaling up vaccine production in low- and middle-income countries 283 (28.6%)
Strengthening surveillance to identify potential pandemic pathogens 351 (35.4%)
Combating misinformation about pandemic threats 691 (69.7%)
Installing adequate ventilation in workplaces and homes 127 (12.8%)
    (Missing) 0
1 n (%)

The EQ VAS records the patient’s self-rated health on a vertical visual analogue scale where the endpoints are labelled ‘The best health you can imagine’ and ‘The worst health you can imagine’. The VAS can be used as a quantitative measure of health outcome that reflects the patient’s own judgement. We observe an average of 83 (SD 12.8), consistent with a representative survey in French-speaking Switzerland reporting a mean EQ-VAS of 81.7 (SD 15.5) (Perneger, Combescure, and Courvoisier 2010).

1.3 Municipality of residence

For each municipality in the canton of Bern, we mapped the number of survey respondents. The map illustrates the geographic distribution of the surveyed population, with a markedly higher concentration of respondents in the city of Bern than in the rest of the canton.

2 General knowledge

2.1 Baseline control variables

Table 3. Understanding check up.
Introductory text N = 9911
Please read the following text carefully before answering the questions: A vector is an organism that can transmit a pathogen (virus, bacterium, or parasite), primarily by feeding on an infected host (human or animal), and then transmitting it to other hosts. Tick-borne encephalitis is a disease transmitted by tick bites. Would you classify it as a vector-borne disease?
    Yes 753 (78.4%)
    No 106 (11.0%)
    I don't know 102 (10.6%)
    (Missing) 30
1 n (%)
Table 4. Preliminary knowledge check-up.
Question N = 9911
Have you heard of the following diseases?
West Nile fever 290 (29.3%)
Dengue 876 (88.4%)
Zika 616 (62.2%)
Chikungunya 195 (19.7%)
Lyme disease 751 (75.8%)
Influenza 929 (93.7%)
Measles 945 (95.4%)
None of these 2 (0.20%)
    (Missing) 0
Have you heard of the following organisms?
Ticks 951 (96.0%)
Mosquitoes 949 (95.8%)
Wasps 920 (92.8%)
Bed bugs 911 (91.9%)
None of these 1 (0.10%)
    (Missing) 0
1 n (%)

A majority of participants answered consistently when linking vectors to disease transmission, but a minority displayed contradictions. About 6% denied ticks or mosquitoes as transmitters while simultaneously identifying them as responsible for disease transmission. In total, 10.7% of respondents contradicted themselves in at least one case. This suggests that while knowledge was generally coherent, a small but notable share of respondents held conflicting beliefs or had difficulties applying knowledge consistently.

Table 5. Logical contradictions in respondents’ answers.
Question N = 9911
Denied tick as transmitter and identified ticks as transmiting a disease
    Consistent 902 (94.1%)
    Contradiction 57 (5.94%)
    (Missing) 32
Denied mosquitoes transmitter and identified mosquitoes as transmiting a disease
    Consistent 896 (94.0%)
    Contradiction 57 (5.98%)
    (Missing) 38
Any of the two contradiction
    Consistent 850 (89.3%)
    Contradiction 102 (10.7%)
    (Missing) 39
1 n (%)

2.1.1 Filtering

To ensure data quality and consistency, we used Supplementary table 3 and Supplementary table 5 to exclude respondents who either lacked a basic understanding of vector-borne disease diseases or provided logically inconsistent answers throughout the questionnaire. This process ensures that responses reflect a reliable snapshot of participants’ knowledge and that the respondents don’t adapt their answers during the completion of the questionnaire. In total, 282 individuals were excluded based on these criteria, leaving a final sample of 709 participants for analyzing the results of the knowledge follow-up questions.

2.2 Item-level accuracy

Table 6. Vector-borne disease test item.
Test item N = 7091
Question : Which of these diseases do you think are vector-borne diseases?
    (Missing) 0
West Nile correctly classified as VBD
    Incorrect 421 (59.4%)
    Correct 288 (40.6%)
Dengue correctly classified as VBD
    Incorrect 98 (13.8%)
    Correct 611 (86.2%)
Zika correctly classified as VBD
    Incorrect 222 (31.3%)
    Correct 487 (68.7%)
Chikungunya correctly classified as VBD
    Incorrect 480 (67.7%)
    Correct 229 (32.3%)
Lyme correctly classified as VBD
    Incorrect 121 (17.1%)
    Correct 588 (82.9%)
Influenza correctly classified as not a VBD
    Incorrect 142 (20.0%)
    Correct 567 (80.0%)
Measles correctly classified as not a VBD
    Incorrect 123 (17.3%)
    Correct 586 (82.7%)
1 n (%)
Table 7. Vector test item.
Test item N = 7091
Question : Which of these organisms transmit diseases to humans?
    (Missing) 0
Ticks correctly identified as transmitting disease
    Incorrect 0 (0%)
    Correct 709 (100.0%)
Mosquitoes correctly identified as transmitting disease
    Incorrect 9 (1.27%)
    Correct 700 (98.7%)
Wasps correctly identified as not transmitting disease
    Incorrect 46 (6.49%)
    Correct 663 (93.5%)
Bed bugs identified as not transmitting disease
    Incorrect 163 (23.0%)
    Correct 546 (77.0%)
1 n (%)
Table 8. Disease–vector matching test item.
Test item N = 7091
Question : Match each disease on the left with its vector on the right (one per row). E.g. ’tick-borne encephalitis’ -> ’ticks’.
TBE correctly matched to ticks
    Incorrect 3 (0.42%)
    Correct 704 (99.6%)
West Nile correctly matched to mosquitoes
    Incorrect 278 (43.4%)
    Correct 363 (56.6%)
Dengue correctly matched to mosquitoes
    Incorrect 77 (11.1%)
    Correct 616 (88.9%)
Zika correctly matched to mosquitoes
    Incorrect 184 (27.7%)
    Correct 480 (72.3%)
Chikungunya correctly matched to mosquitoes
    Incorrect 361 (58.2%)
    Correct 259 (41.8%)
Lyme correctly matched to ticks
    Incorrect 87 (12.4%)
    Correct 613 (87.6%)
Influenza correctly matched to none
    Incorrect 42 (6.62%)
    Correct 592 (93.4%)
Measles correctly matched to none
    Incorrect 48 (7.61%)
    Correct 583 (92.4%)
1 n (%)

2.3 Overall knowledge score

We hereby display a more detailed visualization of the repartition of the overall knowledge score by highlighting the relative contribution of knowledge test items (recognizing organisms as vectors, recognizing diseases as VBDs, matching diseases with their corresponding vector) or associated vectors (Wasp/bed bugs distractors, Ticks, Mosquitoes). The ability to identify vector-borne diseases and knowledge about mosquitoes and mosquito-borne diseases appear as important drivers of the overall knowledge score.

3 Individual exposure : open-ended answers

Most respondents reported vaccination against tick-borne encephalitis (FSME/TBE) as their main preventive measure, often mentioning it explicitly for themselves or their children. A smaller number referred to protecting pets (e.g., with tick collars or treatments) as an indirect preventive strategy. Few participants mentioned other measures such as avoiding tall grass or forests, wearing protective clothing or hats, using repellents (sprays, oils, patches), or employing unconventional approaches such as vinegar, vitamin B, or ceramic bracelets. Overall, vaccination was by far the most commonly cited individual preventive action, with other measures appearing rarely and in isolated cases.

Respondents described a wide range of individual strategies to prevent mosquito bites. Common measures included the use of repellents such as insect sprays, mosquito-repellent candles, incense sticks, essential oils (e.g., lavender, clove, oregano), and specialized diffusers or bracelets. Several participants reported installing or using physical barriers such as mosquito nets, insect screens, or curtains, and others emphasized behavioral measures, including keeping lights off in the evening, ventilating rooms during the day, and avoiding open windows at night. Some mentioned directly eliminating mosquitoes indoors through catching, swatting, or using electric devices. Additional approaches included reducing breeding sites by covering or regularly changing standing water, maintaining bat-friendly gardens, or applying larvicides. A few respondents also referred to vaccination or the use of vitamin supplements as protective measures.

Perneger, Thomas V., Christophe Combescure, and Delphine S. Courvoisier. 2010. “General Population Reference Values for the French Version of the EuroQol EQ-5D Health Utility Instrument.” Value in Health 13 (5): 631–35. https://doi.org/10.1111/j.1524-4733.2010.00727.x.